Currently the leading and trailing ends of photographic film, such as 35 mm film, are square cut during splicing and heat seal splicing tape is applied to join the filmstrips together for continuous processing and printing in a large photo finishing laboratory. At finishing the filmstrip is cut into strips, for example strips of four frames, and returned to the customer along with an attached film splice label. A new photographic system is contemplated which requires the film to be returned to a cartridge, for example the customers original cartridge. This will require filmstrip geometry to be retained by reforming the end of the filmstrip after processing of the spliced film. One method of accomplishing this function is to remove the splice tape by cutting and then re-shaping the cut ends. By cutting the spliced film to remove the splice tape rather than using thermal desplicing methods, concern that adhesive residue on the film ends is being returned to the customer which might cause a future problem in the cartridge is eliminated.
As part of the attachment or detachment process for films, it may be required for the photographic system to accurately and reliably sense the physical end of a filmstrip. This may be necessary to insure that the filmstrip is completely unwound from a film cartridge prior to the detachment operation or the filmstrip is fully positioned prior to an attachment operation. For these functions, the exposed image area of the filmstrip is not important. Most film features (i.e. perforations and holes) are intended as features that identify individual exposure frames or the end of the exposure area and not the physical end of the filmstrip. Technologies exist to sense tension in a web or film features that relate to the exposure area of a film but both schemes are deficient in that sensing of the physical end of the filmstrip is not absolutely confirmed.
U.S. Pat. No. 3,499,202 discloses a machine for cutting a continuous roll of unexposed movie film into controlled lengths for loading into film cartridges and re-shaping the leading and trailing ends of the cut film to facilitate its loading into a cartridge. A punching assembly is provided which simultaneously punches the leading end of the rolled filmstrip and the trailing end of the next filmstrip to be rolled.
U.S. Pat. No. 3,586,258 discloses a method and an apparatus for loading unexposed photographic film in tape form into a cassette. After a length of film is wound onto the cassette the film is stopped and cut to provide a trailing end for the film in the cassette and a leading end of new film to be inserted in a new cassette. A punch is provided for punching the leading end to provide an anchoring means for attaching to the cassette spool.
U.S. Pat. No. 3,854,357 discloses a method and an apparatus for removing an imperfect portion of a web to form trailing and leading web portions, and splicing the web portions to form a continuous perfect web. The apparatus comprises knife blades for separating the imperfect portion and a guiding member for aligning the leading web end with the trailing web end in position to be spliced.
U.S. Pat. No. 4,131,040 discloses an apparatus, for forming holes in the end of a printing blanket, in the form of a template having a locating hole for disposing around a locating pin, holes for receiving a punch, and a clamp for clamping the template against the blanket at a location remote from the locating pin.
U.S. Pat. No. 4,505,039 discloses a seaming tool, for trimming the ends of adjoining floor covering materials to form a joint, in the form of a template which is positioned over the material to be trimmed. A stop is provided to position the template along an end of already laid floor covering and the edge of the material to be trimmed is manually trimmed against the edge of the template.
In the present application the term "end-locating distance" defines a length corresponding to the distance, in a photographic film having a filmstrip exposure area on a portion of the film and a filmstrip trailing end, which is greater than the length of the filmstrip remaining inside a corresponding film cartridge with a spool core to which the trailing end is attached when the film is fully withdrawn and is still attached to the spool core and less than the distance from the end of the exposure area to the physical end of the filmstrip trailing end.